def lscan; gets.split.map(&:to_i); end

a,b = lscan

x = a&(b^((1 << 32)-1))
if x != 0
  p 0
  exit
end
u = b&(a^((1 << 32)-1))
c = u.to_s(2).count('1')
p 1 << (c-1)